Snare recovery system



J1me 1966 J. 'r. Dl GIROLAMO ETAL 3,258,227

"SNARE" RECOVERY SYSTEM 5 Sheets-Sheet 1 Filed June 28, 1963 INVENTOR JUSTIN T. DIGIROLAMO MOSES SIEGEL ATTORNEY Jun 28, 1966 J. T. DI GIROLAMO ETAL. 3,258,227

"SNARE" RECOVERY SYSTEM Filed June 28, 1963 5 Sheets-Sheet 2 INVENTOR. JUSTIN T. DI GIROLAMO MOSES SIEGEL Mug/Lt ATTORNEY June 1966 J. T. Dl GIROLAMO ETAL 3,

"SNARE" RECOVERY SYSTEM 5 Sheets-Sheet 3 Filed June 28, 1963 INVENTOR. T. DIGIROLAMO SIEGEL ATTORNEY June 1966 J. T. DI GIROLAMO ETAL 3,

"SNARE" RECOVERY SYSTEM 5 Sheets-Sheet 4 Filed June 28, 1965 INVENTOR. JUSTIN T. D-GIROLAMO SIEGEL MOSES MLMML,

ATTORNEY June 28, 1966 J. T. DI GIROLAMO ETAL "SNARE" RECOVERY SYSTEM 5 Sheets-Sheet 5 Filed June 28, 1963 INVENTOR.

T. DIGIRQLAMO SIEGEL ATTORNEY United States Patent 3,258,227 SNARE RECOVERY SYSTEM Justin T. Di Girolamo, Blackwood, N.J., and Moses Siege], Philadelphia, Pa., assignors to the United States of America as represented by the Secretary of the Navy Filed June 28, 1963, Ser. No. 291,589 Claims. (Cl. 244-14) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to launching and recovery of aerial test missiles.

United States Patent 3,053,479 to Siegal et al. somewhat sets out the need for equipment by which a test missile may be recovered after being ejected from a launcher. In the recovery device disclosed by the mentioned patent, a cable is attached to the nose of the test missile. Upon ejection of the missile, the slack in the cable is overhauled with rise of the missile and a yielding restraint is applied to the cable with descent of the missile so as to arrest it in mid-air.

Although the invention of United States Patent 3,05 3,- 479 has performed satisfactorily, nevertheless, under certain conditions, as an example, underwater missile shots, the cable has some influence on the results.

Accordingly, an object of this invention is to provide a recovery system which will not hinder the catapulted flight of a test missile; which will recover a test missile with a high probability of causing no damage to the test missile; and which is peculiarly adapted for underwater ejection shots of a test missile.

Other object will become apparent in the specific construction illustrated and described, it being understood that the invention is not limited thereby, since it is cap able of other forms. The phraseology is for description purposes and not intended to limit the invention beyond the terms of the appended claims in view of the prior art.

In the drawing,

FIG. 1 is an elevational view of the invention illustrating the missile and recovery device in readiness for a launching;

FIG. 2 is an enlarged perspective view showing the net of FIG. 1 as it is tied down prior to a launch;

FIG. 3 is similar to FIG. 2 but shows a partial pursing of the net and severing of the tie lines after a raising force has been applied to it;

FIG. 4 is an enlarged view showing details of the connections at the apex of the net.

FIG. 5 is a plan view of the net illustrating the looping of the pursing cables around it;

FIG. 6 is a cross sectional view of one of the pursing clamps;

FIG. 7 is similar to FIG. 1 but shows the net after a recovery of a missile.

In a broad Way, the invention employs a conically shaped net that is suspended by a cable from a tower so that its open bottom is above the missile launcher. After the missile has been launched and has partially entered the net, the net is raised at a rate not to interfere with the rise of the missile. When the missile is at its apogee, it has been enclosed by the net, the bottom of the net having been pursed under it. On missile fallback, an arresting engine tensions the net supporting cable and gently brings the entrapped missile to rest in mid-air.

In detail, referring to the drawing, 10 indicates an aerial type missile disposed in a barrel type launcher 12 seated under a body of Water 14. A boat 16 floats on "ice the water 14 having a tower 18 supporting a boom 20 over the launcher 12.

An arresting engine 22 is mounted on the boat 16. It has a crosshead 24 with a number of sheaves, one of them is indicated at 26, which is attached to a piston 28. Sheaves 26 are movable with the reciprocable motion of piston 28 in its cylinder 32 and relative to a plurality of sheaves 31 fixed to cylinder 32.

The missile 10 is ejected from launcher 12 when pressurized fluid enters the launcher under the missile. The outward movement of piston 28 in the arresting engine 22, as is required for a recovery, is also under the influence of pressurized fluid. Both the launching of the missile and outward movement of piston 28 of the arresting engine are controlled by a single electrical switch, not shown. A suitable electrical and fluid system is presented in United States Patent 3,053,479, with the exception of a conventional timing device which may be placed into the system to momentarily delay the arresting engine after the launch, as may be required.

A net retrieving cable 33 has one end secured somewhere to the arresting engine, not shown, and is reeved between the fixed sheaves 31 and movable sheaves 26. The other end of the retrieving cable, 33, has a socket 34 (FIG. 4) and is directed, by pulleys 35, 36 and 38, up tower 18 and over boom 20 so that it is over launcher 12. Secured to the depending end of the retrieving cable by means of a pendant 39 is a missile retrieving net 40, of sufficient size to receive and encompass a missile.

In form, net 40 is a cone, preferably an octagonal pyramid as shown in FIGS. 1 and 5. It is closed at the apex and opened at its base and is made of a number of interlaced strips, 42 and 44, (FIG. 2) of nylon fabric or other suitable material that furnishes strength with flexibility and permits collapsing the net around a missile. At the apex of the net, there is a metallic cap 46 (FIG. 4). The longitudinally extending nylon strips 44 are secured to the cap in a suitable manner by bolts 48.

The pendant 39 is used to connect the depending end of the retrieving cable to the net 40 and is designed to absorb inertia and stress at the commencement of a net hoisting. It includes two connectors 50 and 52, a tension element 54, a cable guide 56, and a retrieving lanyard 58. The connectors, 50 and 52, are similar. Each is triangular in shape and provided with a bolt receiving aperture, in each of its corners.

The tension element, 54, is an eye-ended bolt having a reduced area 61 which will permit it to part under a tensile force applied at its eye ends.

The cable guide, 56, may take various forms. In effect, the one shown is a plate having connection making bifurcations at opposite ends and a cable passage 66 in between. It is joined at one of the bifurcations to the socketed ends 34, of the retrieving cable 33 and at the other bifurcation to one of the apertures of connector 50. The tension element 54 is also joined at one of its ends to connector 50 and at its other end to the other connector 52 which in turn is secured by a bolt 68 to a lug 62 extending from the nets cap 46. The lanyard 58, of longer length than the tension element 54, is also secured at its ends to each of the connectors 50 and 52.

This construction in the pendant 39 is provided, for one thing, to minimize the inertia and stress in the retrieving cable 33, especially at the start of raising of net 40 and also to produce an initial jolt to the net which will free it from its tie downs, as will be realized hereafter. When an upward pull is first applied, the tension element 54 parts at groove 61 separating the connectors 50 and 52 to the full length of lanyard 58. Further force from retrieving cable 33 is transferred through the lanyard 58 to raise the net 40.

a,2ee,227

To hold net 40 open at its base over launcher 12, a number of tie lines 72 (FIG. 1) extend from the edge of the net to buoys 74, anchored by guy lines 76. The buoys 74 are held in position by a float line 78 joining them together.

Raising net 40 requires its release from the tie lines 72. For this purpose, each tie line includes a tension element 80, FIG. 2, which may be eye-ended as that described for pendant 39, that is secured at its ends to the net and tie line in some feasible manner, as shown. Each of the tie line tension elements 80 has the usual weakened area or groove 81 which permit it to be pulled apart after a predetermined raising force is applied to the net retrieving cable 33. The tie line tension elements 80 are designed to part shortly after the tension element in the pendant 39, at the apex of the net, has parted and with the initial application of force or jolt to the net by the retrieving cable. As previously mentioned, the net is closed around the missile and raised as the missile rises.

For closing the net 40, there are a number of guide rings 82 (FIGS. 2 and 5) secured at the base of the net. From one side of the net, a pursing cable 84 passes through the guide rings 82 that are disposed on the opposite side of the net so as to encircle it, and has its ends extend through a pulley 86 mounted on a buoy 88. The latter is fixed in position by a number of guy lines 90 (FIG. 1). The ends of pursing cable 84 are secured to one end of a tension element 92 (FIG. 4) having the usual parting groove 93. The other end of the tension element 92 is secured to an end of a transfer cable 94 suspended from the cable guide 56 in the pendant 39. The transfer cable 94 is freely movable in the cable guide 56 and its other end is connected to a similar tension element 92' which in turn is secured to a second pursing cable 84' which is looped around the net from an opposite direction to that of pursing cable 84. As shown, it passes through the guide rings 82 and its ends are directed upwardly by a pulley 86' on a second buoy 88 disposed diametrically opposite to buoy 88. A pursing lanyard, 96 and 96', is provided for each pursing cable to maintain its connection with the transfer cable 94 upon separation of its tension element.

To prevent opening of the net after it has been pursed under the weight of an entrapped missile, each end of each pursing cable is provided with a pursing clamp 95. It has a sleeve 97 (FIG. 6) secured in some suitable manner to the base of the net which has a tapered internal surface 98 and a ball 89. The cable passes through the sleeve freely in a pursing direction, but its movement in an opposite direction causes a wedging of the ball 89 between the cable 84 and the sleeves tapered surface 98.

In operation, the test missile 10 is launched with the admission of pressurized fluid into the launcher 12. After a period of time, fluid pressure is supplied to cyl inder 30 of arresting engine 22 to move crosshead 24 outwardly. Retrieving cable 33, is drawn into the arresting engine raising its depending end.

The initial upward movement of retrieving cable 33 separates the tension element 54 in pendant 39, and the net is jolted by the force transferred to it through the lanyard 58. The jolt breaks the tension elements 80 in the tie lines 72 at the bottom of the net 40 and frees it for upward movement. The net rises with the retrieving cable 33 as does the transfer cable guide 56.

The rising transfer guide 56 exerts a pull through the transfer cable 94 to the pursing lines 84 and 84'. Since the pursing lines are reeved through the pulley 86 and 86 to the fixed buoys 88 and 88', a pursing action takes place with this upward movement of the transfer cable guide 56. And because the net 40 is also rising, it being attached to the retrieving cable 33 and the pursing cables 84 and 84' being looped around it, this also causes a pursing action. Consequently, there are two simultaneous pursing actions which quickly close the net. time of pursing, the missile is within the net.

With further rising of the retrieving cable 33, the force on the transfer cable 94 is increased until eventually the tension elements, 92 and 92', in the pursing system rupture. The net continues to be raised thereafter and its rate is fast enough not to cause interference with the flight of the missile within it.

By the time the missile has risen to its apogee, the slack in the pursing lanyards, 96 and 96', is depleted and they are tensioned.

From its apogee the missile falls back and settles in the net. Its retention is assured by the pursing clamps, 95, which prevent withdrawal of the pursing cables and opening of the net. The overhaul of the retrieving cable 33 is then stopped and recovery of the missile is completed; it being suspended in mid-air as shown in FIG. 7.

Should the missile launch be off-center of the net, the transfer cable 94 will shift in the transfer cable guide 56, and pursing action will in no way be affected.

The method of lowering the missile and reloading it into the launcher 12 is not a part of this invention and will not, therefore, be described.

While the invention has been illustrated and described with one specific embodiment, obviously many modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. Apparatus for recovering an aerial test vehicle which is ejected to a predetermined height above a surface, said apparatus comprising:

(a) an overhead support above said predetermined height;

(b) a retrieving cable suspended from said support having a depending end adapted to be raised toward said support;

(c) a conically shaped flexible material net disposed to receive the test vehicle through an opening at its base;

(d) a pendant securing the depending end of the retrieving cable to the apex of the net, said pendant including a tension element and a parallel connected flexbile lanyard, the tension element being arranged to part upon the application of a predetermined stress and transfer lifting force to the lanyard and thereby reduce the inertia and stress on th lanyard as the net begins to rise;

(e) and pursing means encircling said net for closing it at its base as the net is raised to a predetermined elevation by the retrieving cable.

2. The device of claim 1 wherein said pursing means includes a pursing cable looped around the base of said net, an anchor on said surface, and a pulley mounted on said anchor, said pursing cable being reeved through said pulley and attached to the depending end of said retrieving cable.

3. Apparatus for recovering an aerial test vehicle which is ejected to a predetermined height above a surface comprising:

(a) an overhead support disposed above said height;

(b) a retrieving cable having a depending end suspended from said support and adapted to be raised toward said support;

(c) a conically shaped net secured at its apex to said depending end of said retrieving cable;

((1) means detaohably securing said net to said surface for holding said net open;

(e) a pursing cable encircling said net having ends xtending to one side of said net;

(f) a cable pulley secured to said surface;

(g) a tension element;

(h) the ends of said pursing cable reeved through said cable pulley and secured to one end of said tension element;

At this (i) a second pursing cable encircling said net having ends extending to a side opposite of said one side of said net;

(1') a second pulley secured to said surface;

(k) a second tension element;

(1) the ends of said pursing cable reeved through said second pulley and secured to an end of said tension element;

(In) a cable guide secured to said depending end of said retrieving cable;

(n) a transfer cable passing through said cable guide having an end secured to the other end of each of said tension elements;

(0) and a lanyard of predetermined length for each of said tension elements having an end attached to each end of said tension element.

4. The apparatus of claim 3 including a pendant having a pendant tension element secured by its ends to the apex 6 of said net and to said depending end of said retrieving cable and a lanyard securing the ends of said pendant tension element together while permitting their separation to a set distance.

5. The device of claim 4 including means for raising said net with said vehicle therein at a rate not to interfere with the flight of said vehicl and for closing the net at the end of fiight of said vehicle so as to restrain the fall of said vehcile to said surface.

References Cited by the Examiner UNITED STATES PATENTS 2,723,481 11/1955 Schwartz 43102 X BENJAMIN A. BORCHELT, Primary Examiner.

M. F. HUBLER, Assistant Examiner. 

1. APPARATUS FOR RECOVERING AN AERIAL TEST VEHICLE WHICH IS EJECTED TO A PREDETERMINED HEIGHT ABOVE A SURFACE, SAID APPARATUS COMPRISING: (A) AN OVERHEAD SUPPORT ABOVE SAID PREDETERMINED HEIGHT; (B) A RETRIEVING CABLE SUSPENDED FROM SAID SUPPORT HAVING A DEPENDING END ADAPTED TO BE RAISED TOWARD SAID SUPPORT; (C) A CONICALLY SHAPED FLEXIBLE MATERIAL NET DISPOSED TO RECEIVE THE TEST VEHICLE THROUGH AN OPENING AT ITS BASE; (D) A PENDANT SECURING THE DEPENDING END OF THE RETRIEVING CABLE TO THE APEX OF THE NET, SAID PENDANT INCLUDING A TENSION ELEMENT AND PARALLEL CONNECTED FLEXIBLE LANYARD, THE TENSION ELEMENT BEING ARRANGED TO PART UPON THE APPLICATION OF A PREDETERMINED STRESS AND TRANSFER LIFTING FORCE TO THE LANYARD AND THEREBY REDUCE THE INERTIA AND STRESS ON THE LANYARD AS THE NET BEGINS TO RISE; (E) AND PURSING MEANS ENCIRCLING SAID NET FOR CLOSING IT AT ITS BASE AS THE NET IS RAISED TO A PREDETERMINED ELEVATION BY THE RETRIEVING CABLE. 